Graphite is the major anode material of commercial lithium‐ion batteries (LIBs), and thus improving its cycling stability is an effective approach to extend battery life. In this study, succinic anhydride group, methoxyethanol and methoxypolyethylene glycol segments are chemically bonded to the surfaces of graphite particles by the Diels‐Alder and the subsequent esterification reactions. The synthesized functionalized graphites are excellent in water‐dispersibility. The electrochemical results indicate that the functionalization slightly reduces the initial coulombic efficiencies of the graphite anodes, but significantly changes the cycling stability and high C‐rate performance of the corresponding lithium‐ion cells. In particular, the cell based on the graphite functionalized by long‐chain polyethylene glycol exhibits an improvement of 24.1 % in cycle life compared with the pristine graphite. Further analysis shows that these trace organic groups change the properties of the solid‐electrolyte interface (SEI) layer depositing on the graphite surfaces, and therefore influence the performance of the cells.

中文翻译：

---

表面功能化石墨作为锂离子电池的长寿命阳极材料

石墨是商用锂离子电池（LIB）的主要负极材料，因此提高其循环稳定性是延长电池寿命的有效方法。在这项研究中，琥珀酸酐基团，甲氧基乙醇和甲氧基聚乙二醇链段通过Diels-Alder及其随后的酯化反应化学键合到石墨颗粒的表面。合成的功能化石墨具有优异的水分散性。电化学结果表明，官能化会稍微降低石墨阳极的初始库伦效率，但会显着改变相应锂离子电池的循环稳定性和高C速率性能。特别是，基于被长链聚乙二醇官能化的石墨的电池表现出24的改进。与原始石墨相比，循环寿命为1％。进一步的分析表明，这些痕量有机基团改变了沉积在石墨表面上的固体电解质界面（SEI）层的性质，从而影响了电池的性能。